Dysphagia, a condition characterized by difficulty in swallowing food and liquids, can be present in patients suffering from stroke, head injury, neurological disorders, and other cognitive and motor problems. It may also occur as a result of aging, disability, or as a transient condition following some surgeries. As a result of dysphagia, patients may also suffer from dehydration and nutritional deficits.
When a person suffering from dysphagia attempts to swallow thin liquids, the bolus may tend to go down the bronchus and into the lungs, causing coughing, choking and even aspiration, which can lead to pneumonia. In order to maintain nutrition and hydration, these patients are sometimes given very small volumes, typically about one teaspoon. These smaller boluses can be more readily handled, often without aspiration problems.
Various devices, liquid thickeners and other products have previously been developed to assist patients with dysphagia, but these typically do not allow a fixed volume to be delivered, with a normal drinking motion, without the assistance of a caregiver.
Limited flow drinking cups are designed to provide a fixed, metered amount of liquid to a user. A typical limited flow cup includes a cup body having a cover that defines an opening through which fluid can pass. Metering is provided by a three-piece assembly including (a) the cover, (b) a tube that is fixed to the cover at the opening and extends downward into the cup body, and (c) a tiny, self-contained metering cup mounted at the lower end of the tube. The metering cup has an open end that faces in a generally sideways direction. Prior to drinking, the cup body contains liquid up to a given liquid level, the metering cup is full of liquid, and the tube is filled with liquid up to the liquid level within the cup body. The metering cup and the portion of the tube that is below the liquid level in the cup body together define a metering chamber having a limited volume. When the user tilts the limited flow cup to a drinking position, the liquid within the metering chamber flows through the tube and out through the opening to the user. When the cup body is in the drinking position, the open end of the metering cup generally extends above the liquid level within the cup body, so that fluid cannot flow into the metering cup. As a result, only the volume within the metering chamber is dispensed during a single drinking motion.